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A Feasible Design of Power Packet Dispatching System / 電力パケット伝送システムの実現可能な設計Katayama, Shinji 23 March 2022 (has links)
付記する学位プログラム名: 京都大学卓越大学院プログラム「先端光・電子デバイス創成学」 / 京都大学 / 新制・課程博士 / 博士(工学) / 甲第23902号 / 工博第4989号 / 新制||工||1779(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 引原 隆士, 教授 土居 伸二 特定教授 中村 武恒 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Development of a Dynamic Performance Management Framework for Naval Ship Power System using Model-Based Predictive ControlShi, Jian 13 December 2014 (has links)
Medium-Voltage Direct-Current (MVDC) power system has been considered as the trending technology for future All-Electric Ships (AES) to produce, convert and distribute electrical power. With the wide employment of highrequency power electronics converters and motor drives in DC system, accurate and fast assessment of system dynamic behaviors , as well as the optimization of system transient performance have become serious concerns for system-level studies, high-level control designs and power management algorithm development. The proposed technique presents a coordinated and automated approach to determine the system adjustment strategy for naval power systems to improve the transient performance and prevent potential instability following a system contingency. In contrast with the conventional design schemes that heavily rely on the human operators and pre-specified rules/set points, we focus on the development of the capability to automatically and efficiently detect and react to system state changes following disturbances and or damages by incooperating different system components to formulate an overall system-level solution. To achieve this objective, we propose a generic model-based predictive management framework that can be applied to a variety of Shipboard Power System (SPS) applications to meet the stringent performance requirements under different operating conditions. The proposed technique is proven to effectively prevent the system from instability caused by known and unknown disturbances with little or none human intervention under a variety of operation conditions. The management framework proposed in this dissertation is designed based on the concept of Model Predictive Control (MPC) techniques. A numerical approximation of the actual system is used to predict future system behaviors based on the current states and the candidate control input sequences. Based on the predictions the optimal control solution is chosen and applied as the current control input. The effectiveness and efficiency of the proposed framework can be evaluated conveniently based on a series of performance criteria such as fitness, robustness and computational overhead. An automatic system modeling, analysis and synthesis software environment is also introduced in this dissertation to facilitate the rapid implementation of the proposed performance management framework according to various testing scenarios.
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Insulative (Direct Current) Dielectrophoretic Foul-Less Filtration in Microfuidic SystemsWhitman, Matthew A A 01 March 2020 (has links) (PDF)
Filtration is a technology that is used almost ubiquitously in society from uses raging from filtration of macroparticles from water to pharmaceutical grade filtration products to remove anything larger than a protein. However, with such a wide range of uses, most filtration products have the same issue; membrane clogging (fouling) that prevents continuous use and requires frequent maintenance. This thesis hypothesizes that by applying a direct current (DC) to an insulating array of posts, they will create a foul-less insulative dielectrophoretic filter (iDEP) that does not clog since particles will levitate above the insulating array.
This thesis tested an inherited device (legacy device) and found that its design did not perform the desired foul-less filtration operation under the tested conditions. Therefore, using COMSOL simulations, the conditions of testing and improved deign were developed to fruition. These devices were fabricated and tested and found to successfully levitate yeast particles above the foul-less filtration array using a direct current insulative dielectrophoretic (iDEP) filter. Additionally, different post geometries were observed and how they affect the dielectric force on particles. Although a foul-less filter was not successfully developed over the course of this thesis, the groundwork for development of DC iDEP has been set.
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The electrolytic production of lead chromate using periodically reversed direct current and superimposed alternating current on direct currentDoumas, Basil C. January 1955 (has links)
It was the purpose of this investigation to study the effect of varying the direct to reverse time ratio of periodically reversed direct current from 1.0 to 20.0 on the electrolytic production of lead chromate at an average anode current density of 0.0059 amperes per square centimeter, and to study the effect of 60 and 502.3 ± 7.7 cycles per second from 0.00113 to 0.01546 amperes per square centimeter of peak superimposed alternating current on direct current on the yield of lead chromate prepared by the electrolysis of a bath containing potassium chromate and sodium nitrate between lead electrodes.
Electrolysis of a bath containing 3.60 grams of potassium chromate, 11.62 grams of sodium nitrate, end 1000 grams of water with simple direct current yielded 6.07 grams of lead chromate per ampere-hour, the purity being 92.7 percent lead chromate. The anode current density was 0.0049 amperes per square centimeter, and the current efficiency was 98.1 percent. During the electrolysis, by maintaining the ph of the electrolyte at 6.0, by adding a solution to 2.0 weight percent chromic acid, the purity of the product was increased.
Electrolysis of the same bath using periodically reversed direct current yielded 4.53 grams of lead chromate per ampere-hour, the purity being 93.9 percent lead chromate. The time ratio was 20.0, the anode current density was 0.0049 amperes per square centimeter, and the current efficiency was 66.75 percent. Decreasing the direct to reverse time ratio gave lower yields and purities. Apparently, there is no advantage in using periodically reversed direct current over the use of direct current for this reaction under the above conditions.
Electrolysis of the same bath with alternating current superimposed on direct current yielded 5.49 grams of lead chromate per direct current ampere-hour, at a purity of 99.4 percent lead chromate, when using 494.7 cycle alternating current. The alternating and direct current densities were 0.0078 and 0.0048 amperes per square centimeter, respectively. This was the purest product obtained in this investigation. Use of 60 cycle alternating current yielded 3.83 grams of lead chromate per direct current ampere-hour, at a purity of 93.9 percent lead chromate. The alternating and direct current densities were 0.00141 and 0.00484 amperes per square centimeter.
Further experiments were made using direct current and periodically reversed direct current on a bath containing 6.80 grams of potassium chromate, 8.14 grams of sodium nitrate, and 1000 grams of water. Results from these electrolytes were much poorer than those obtained with the previous bath, so no experiments with superimposed alternating current on direct current were carried out with this latter bath. / Master of Science
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Nonlinear algorithms for fast and robust control of electrical drivesBorojević, Dušan January 1986 (has links)
Several new nonlinear algorithms for speed control of electrical drives are developed. They are compared with the algorithms for integral-proportional (I-P) control, sliding mode control (SLM) and adaptive control which uses the torque and parameter observer. To achieve fast and robust response, all algorithms use very large gains.
In a new, variable limit PI (VLPI) control algorithm, integrator windup is completely prevented by using a high gain, "variable dead zone" nonlinearity as a local feedback over the integrator.
Recently proposed soft variable structure (SVS) control, derived by using the Liapunov direct method, is modified so that the algorithm can be implemented with only the output measurements. Proper operation is achieved for any value of the output variable. The new control is very robust, but exhibits a steady state error.
Two versions of the adaptive PI (API) control algorithm are developed that have fast and robust transient response with zero steady state error. The SVS API version operates similarly as the modified SVS control, but does not have its drawbacks. The SLM API version operates like the SLM control during large transients, and like VLPI control when close to the steady state. The local stability of the control is proved using the "small gain theorem". Its global behavior is analyzed by describing functions.
Very good operation of the SVS API speed control within the proportional position loop is demonstrated. Faster transient response is achieved by implementing the SLM adaptive proportional control in the position loop. The operation is the same as the operation of the SLM API control in the speed loop.
Similarity between modified SVS control, and classical adaptive algorithms is shown. API control, All the algorithms are simulated and compared for twofold and tenfold changes in plant parameters. The experimental verification of the results for I-P control, SLM control, and modified SVS control, are presented.
Theory of the new algorithms is general, such that the results are applicable to any SISO plant that can be stabilized. / Ph. D.
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A heat transfer finite element model of a high speed DC electric motorGrosse, Ian Royce January 1983 (has links)
A finite element heat transfer model of a high speed direct current electric motor is presented. The two dimensional axisymmetric model incorporates the motor rotor assembly, stator windings, stator laminations, stator end windings, and the motor housing. Power dissipation is modeled as Joule heating in the motor winding elements and iron core losses in the stator laminations. The two-dimensional axisymmetric model is preprocessed using a two dimensional mesh generator. Results are postprocessed with a two-dimensional contour plotting routine and compared to experimental results. Based on experimental data adjustments are made and overall correlation is good. / M.S.
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High voltage direct current (HVDC) in applications for distributed independent power providers (IPP)Giraneza, Martial January 2013 (has links)
Thesis submitted in fulfillment of the requirements for the degree
Master of Technology: Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2013 / The development of power electronics did remove most of technical limitations that high voltage direct current (HVDC) used to have. HVDC, now, is mostly used for the transmission of bulk power over long distances and for the interconnection of asynchronous grid. Along with the development of the HVDC, the growth of power demand also increased beyond the utilities capacities. Besides the on-going increasing of power demand, the reforms in electricity market have led to the liberalization and the incorporation of Independent power providers in power system operation. Regulations and rules have been established by regulating authority for grid integration of Independent power providers. With the expected increase of penetration level of those new independent power providers, result of economic reason and actual green energy trend, best method of integration of those new power plants are required.
In this research HVDC technology, namely VSC-HVDC is used as interface for connecting independent power providers units to the grid. VSC-HVDC has various advantages such as short-circuit contribution and independent control of active and reactive power. VSC-HVDC advantages are used for a safe integration of IPPs and make them participate to grid stabilization. MATLAB/Simulink simulations of different grid connected, through VSC-HVDC system, IPPs technologies models are performed.
For each IPP technology model, system model performances are studied and dynamics responses during the disturbance are analyzed in MATLAB/ Simulink program. The simulation results show that the model satisfy the standard imposed by the regulating authority in terms of power quality and grid support. Also the results show the effect of the VSC-HVDC in preventing faults propagation from grid to integrated IPPs units.
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Analysis of the energy consumption of the powertrain and the auxiliary systems for battery-electric trucks / Analys av energiförbrukningen i drivlinan samt för hjälpsystemen för batterielektriska lastbilarSong, Guanqiao January 2020 (has links)
The electrification of the truck is crucial to meet the strategic vision of the European Union (EU) to contribute to net-zero greenhouse gas emissions for all sectors of the economy and society. The battery-electric truck is very efficient to reduce the emissions and has also a lower Total Cost of Ownership (TCO) compared to diesel trucks. Thus, the energy consumption of the battery-electric truck needs to be analysed in detail, and the differences in the conventional powertrain, recuperation by regenerative braking during driving and charging during standing, need to be considered. This master thesis aims to analyse the energy consumption of the battery-electric truck during driving and standing charging. For driving cycle simulation the Vehicle Energy Consumption calculation TOol (VECTO) and MATLAB are used. Different variations, such as payload, rolling resistance, air drag, and Power Take Off (PTO), are considered in the driving cycle simulation. The driving cycle simulation is verified by calculating the energy balance and compared with the on-road test results. For the standing charging simulation, MATLAB is used to analyse the charging loss with different battery packs and charging speeds. The results are shown with the Sankey diagram and other illustrative tools. Seen from the simulation results, the usable energy of the battery pack is enough for the truck to complete the designed driving cycle. The main loss in the powertrain is the Power Electronic Converter (PEC) and the electric machine. To increase the range and reduce energy loss, using a higher efficiency PEC and electric machine is an efficient method. For the charging simulation, the current Combined Charging System (CCS) standard charging station can charge the battery-electric truck with adequate voltage and reasonable charging time. The main loss during the charging comes from the charging station. / Elektrificering av lastbilen är avgörande för att uppfylla Europeiska Unionens (EUs) strategiska vision att bidra till nettonollutsläpp av växthusgaser för alla sektorer i samhället. Den batterielektriska lastbilen är väldigt effektiv för att reducera utsläppen och är också mer ekonomisk med en lägre Total Cost of Ownership (TCO) jämfört med diesel lastbilar. Således behöver energiförbrukningen för den batterielektriska lastbilen analyseras i detalj, och skillnaderna i den konventionella drivlinan, återhämtning genom regenerativ bromsning under körning och laddning, måste övervägas. Detta examensarbete syftar till att analysera energiförbrukningen för den batterielektriska lastbilen under körning och laddning. För körcykelsimuleringar används the Vehicle Energy Consumption calculation TOol (VECTO) och MATLAB. Olika variationer, såsom nyttolast, rullmotstånd, luftmotstånd och Power Take Off (PTO), beaktas i körcykelsimuleringen. Körcykelsimuleringen verifieras genom att beräkna energibalansen som jämförs med experimentella testresultat utförda på väg. För laddningssimuleringen används MATLAB för att analysera laddningsförlusten med olika batteripaket och laddningshastigheter. Resultaten visas med Sankey diagram och andra illustrativa verktyg. Simuleringsresultaten visar att batteripaketets användbara energi är tillräckligt för att lastbilen ska kunna slutföra den planerade körcykeln. Den största förlusten i drivlinan är kopplat till the Power Electronic Converter (PEC) och den elektriska maskinen. För att öka räckvidden och minska energiförlusten är det ett effektivt sätt att en använda PEC och en elektrisk maskin med högre effektivitet. För laddningssimuleringen kan den nuvarande stationen med Combined Charging System (CCS) standard ladda batteriladdaren med tillräcklig spänning och med rimlig laddningstid. Huvudförlusten under laddningen kommer från laddstationen.
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Nuolatinės srovės keitiklio alternatyviems energijos šaltiniams kūrimas ir tyrimas / The Development and Investigation of Direct Current Converter for Alternative Energy SourcesPlatakis, Andrius 02 July 2010 (has links)
Darbe nagrinėjami ir tiriami nuolatinės srovės keitikliai atsinaujinančios energijos šaltiniams. Pateikiami duomenys apie bendrą elektros energijos gamybą ir gamybą iš atsinaujinančių energijos šaltinių Lietuvoje ir pasaulyje. Pirmajame skyriuje nagrinėjamos pagrindinės nuolatinės srovės keitiklių struktūros, pateikiamos jų topologijos, analizuojamos išraiškos parametrams skaičiuoti, pateikiami valdančiųjų signalų formavimo algoritmai ir signalų epiūros. Antrajame skyriuje nagrinėjamos nuolatinės srovės keitiklių (inverterių), keičiančių nuolatinės srovės šaltinio įtampą į kintamąją įtampą, struktūros. Analizuojamos šių keitiklių topologijos, valdymo principai, signalų epiūros, signalų formavimo algoritmai, inverterių savybės, nagrinėjamos išraiškos parametrams apskaičiuoti. Trečiajame skyriuje analizuojamas inverterio išėjimo filtras. Pateikiamos pagrindinės šio filtro topologijos, aptariamos jų savybės, pateikiamos signalų epiūros, analizuojamos išraiškos filtro parametrams apskaičiuoti. Ketvirtajame skyriuje pateikiami inverterio su išėjimo filtru modeliavimo ir eksperimentinio tyrimo rezultatai. Tyrimams suprojektuotas ir surinktas 1 kW galios inverteris su filtru, jo darbo valdymui ir valdančiųjų signalų inverterio raktams formavimui panaudotas mikrokompiuteris su mikrovaldikliu. Gauti tyrimų rezultatai pritaikyti kuriant keitiklį saulės elementų baterijoms. Kiekvieno skyriaus pabaigoje pateikiamos išvados. Baigiamojo darbo pabaigoje pateikiamos apibendrinančios išvados. / The work focuses on direct current (DC) converters for alternative energy sources. The data about the general production of electricity and the production of electricity from alternative energy sources in Lithuania and in the world is presented. In the first section the structures and topologies of DC-DC converters are analyzed, the signal formation algorithms and plots of the signals are given and discussed. In the second section the structures and topologies of DC-AC (Alternating Current) converters are analyzed, the signal formation algorithms and plots of the signals are presented. In the third section the output filter is analyzed. The topologies, characteristics, signal plots and equations are presented. In the fourth section the simulation and experimental investigation results are presented and discussed. The 1 kW DC-AC converter with output filter was designed for experimental investigation and a microcontroller-based microcomputer was used for generation of signals for control of converter output transistors. The obtained investigation results were employed for development of the converter for the solar panel. Conclusions in the each section of the thesis are given. General conclusions are formulated at the end of the work. Thesis consist of: 88 p. text without appendixes, 77 pictures, 9 tables, 28 bibliographical entries. Appendixes included.
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Dopaminergic Modulation of Neuroplasticity in Humans- Contribuition of Receptor Subtypes and DosageFresnoza, Shane 04 September 2014 (has links)
No description available.
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